Internal-combustion engine



Nov. 11 1924.

K. O. KELLER INTERNAL COMBUSTION ENGINE Filed July 5 1923 2 Sheets-Sheet 1 Nov. 11 1924. 1.515391 K. o. KELLER INTERNAL COMBUSTION ENGINE Filed July 5 L923 2 Sheets-Sheet 2 INYENTQR 4.0 mm 44% W,

' curtain jet.

KARL OTTO KELLER, 0F SUNDERLAND, ENGLAND, ASSIGNOE OF GENE-HALF TO ROBERT FILE DOXJEOBD, OF SUNDE RLAND, DURHAM, ENGLAND.

INTERNAL-COMBUSTION ENGINE.

Application filed July 5,

To all whom it may concern: 7

Be it known that I, KARL O'r'ro KELLER, a citizen of the Swiss Confederation, residing at Sunderland, Durham, England, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

Internal-combustion engines operated by liquid-fuel are known in which the cylinder is provided with means whereby an entering air-stream exerts in known manner a rotative thrust on the body of air in the cylinder into which the liquid-fuel is ultimately to be injected and causes that body to whirl in the cylinder about the cylinderaxis or about an axis near the cylinder-axis and parallel or substantially parallel therewith; further, these engines have been provided with a fuel-oil spraying device delivering fuel-oil as a flat fan-shaped jet of fuel-oil spray into the whirling body of air, this delivery having been characterized not by the shape of the jet but by the setting of said spraying device in such relation to the cylinder-wall that the flat fanshaped jet has constituted itself a curtain extending into the whirling body of air lengthwise of that body (as distinct from normal to the axis of whirl thereof) and lying approximately in the plane containing the axis about which the aforesaid body whirls. The flat fan-shaped jet thus situated in relation to the whirling body of air is herein termed for the sake of brevity the curtain jet.

Engines fitted with the curtain jet emloyed as above, have shown a material increase in efiiciency over engines furnished with other known forms of jet, because of the turbulence set up in the cylinder contents before and during the period of combustion by the passage of the air through the But it has been found in these engines that the cylinder-walls are injured by that portion of the combustion of the fuel which takes place nearest the cylinder-walls.

It is the object of the present invention to retain the advantages of the combination of the whirling body of air with the curtain jet but to eliminate as far as is possible and by a displacement of the combustible charge such as is hereinafter described, the combustion of fuel close to the cylinder-wall, and also to obtain in the act of displacing it a 1923. Serial No. 649,531.

concentration of the charge in which a turbulence 1s lmparted to it additional to that which is given to it by the whirling mo-' tion above referred to, this concentration and added turbulence giving the engine an increased thermal efiiciency over that which is due to the employment of the curtain jet in combination with the whirling body of air: this increased thermal efficiency is due in part to the additional turbulence, in part to the closer approach to one another of the airand oil-elements of the charge during the displacement aforesaid, and 1n part to a lessening, by keeping combustion further from them, of the amount of heat passing from the burning charge to the cylinder walls.

Accordingly the present invention comprises the employment in an internal-combustion engine cylinder of the following combination z-A combustion-chamber within the cylinder preferably with its centre in the longitudinal axis thereof, the said chamber having two concaved walls with their concavities presented towards one another in the said axis, between which walls there is relative movement in the axial line, means for injecting the air for combustion into the combustion-chamber so that it has a whirling motion about an axis coaxial or parallel with the axis of the cylinder together with a fuel-injecting device that is set to deliver a flat fan-shaped jet of fueloil spray into the aforesaid whirling body of air between the two concaved walls as a curtain situated in the plane containing the axis about which the whirling of the aforesaid body was primarily set up. Of the concaved walls each is preferably approximately hemispherical on its exposed face. One wall can be the top end-wall of a lower piston presenting a concave surface upwardly to the lower end-wall of an upper piston or cylinder-cover which is contained in the same cylinder and which presents a similar concaved surface downwardly. The two concaved surfaces, when they are close together, as at the end of the compression-stroke, contain between them a chamber cut off from the cvlinder-wa-ll save for a narrow equatorial band thereof, exposed only by reason of the necessary small clearance between the ends of the pistons or between the piston and the cover, as the case may be.

Each concave surface constitutes-an annular wedge and as these wedges approach one another upon the approach of the piston to the cover or to another piston, they displace from the neighbourhood of the cylinder-walltowards the centre of the combustion-chamber the air and injected oil, and in this dis lacement there is imparted to the airan oil-elements of the charge a turbulence additional to that imparted to them by the whirling motion of the body of air hereinbefore referred to, and at the same time the cylinder-walls are shielded.

In the accompanying drawings, which illustrate diagrammatically various embodiments of this invention- Figure 1 is a central vertical section of a c linder havin two 0 positely-moving pis-lv y g p ment is that the fuel spray is admitted as two curtain jets at diametrically opposite tons in it;

Figure 2 is a section on the line 22 of Figure 1;

Figure 3 is a vertical section of a singlepiston engine;

Figure 4 is a section on the line H of Figure 3;

Figure 5 is a vertical section of a modified construction of engine;

Figure 6 is a section on the line 6-6.of Fi re 5;

igure 7 is a vertical central section of a double-acting engine;

Figure 8 is a section on the line 88 of Figure 7 and Figure 9 is a part view showing the lower end of the cylinder in a section at right-angles to the plane of section of Figure 7.

Like reference characters indicate like parts throughout the drawings.

Referring first to Figures 1 and 2, the cylinder, indicated generally by the reference' 10, has two pistons 11, 12 arranged to reciprocate in opposition in it. These two pistons are provided respectively with heads 13, 14 in which there are formed hemispherical recesses 15, 16, so that when the two pistons approach one another a substantially spherical chamber is formed, this chamber being separated from the cylinder wall by the thickness of the metal of the heads of the pistons except along the narrow equatorial band 17 which is the clearance between the two pistons when they are nearest to one another.

Two or more spraying nozzles are mounted on the cylinder wall opposite the gap 17, as shown .at 19, 20 respectively, these nozzles being arranged to inject a flat curtain spray of fuel into the chambers 15, 16; The heads of the pistons are cut away as at 21 to form narrow grooves permitting the correct spreading of this curtain spray.

The cylinder 10 is provided with inlet ports 22 for scavenging air, these ports be: ing so situated as to be uncovered by the pisileiaaet arranged that the scavengin through them receives a W air admitted ir mg movement .when it enters the cylinder 10; The ports component of motion axially along the cylin-- der 10.

The exhaust ports for the cylinder are provided at 24 being so situated as to be uncovered by the piston 12, 14 when it is at the end of its out stroke, these exhaust ports being situated at the opposite end of the cylinder from the scavenging air inlet ports 22.

- The characteristic feature of this arrangepoints of the substantially spherical combustion chamber.

Tn Figures 3 and 4, a single-acting singlecylinder engine is illustrated. The cylinder 25 is provided with a cylinder-head 26 having a substantially hemispherical recess 27. The piston 28 is provided with a head 29 having a similar hemispherical recess 30 which co-operates with the recess 27 to rovide a substantially spherical combustionchamber. The fuel oil is admitted by means of asingle spraying device 31 which is situated in the axis of the cylinder so as to distribute the fuel in a fan-shaped spray across a diametral plane of the spherical combustion-chamber 27, 30.

Scavengingair is admitted through ports 32 (Figures 3 and 4) which are so situated as to be uncovered by the piston at the end of its out stroke, and these ports moreover are so arranged as to impart an upward whirling movement to the scavenging air, as indicated by the arrows 33. The exhaust ports are indicated at 34, and these are so positioned as also to be uncovered by the piston at the end of its out stroke.

The construction illustrated in Figures 5 and 6 is similar to the construction illustrated in Figures 3 and 4 and the same reference characters are used to designate the various parts, except that instead of the single fuel-spraying nozzle 31, two of such nozzles 35 are provided, these opening through the wall of the cylinder at the open equatorial band aforesaid of the spherical combustion-chamber 27, 30, and injecting each a fan-shaped spray in a diametral plane of the combustion-chamber aforesaid.

, Figures 7, 8 and 9 illustrate an arrangement of double-acting engine. The cylinder 36 is closed at each end byheads 37, 38, each of which is formed with a substantially hemispherical recess 39, 40, respectively; a trunk piston 41 is formed at its ends with ton 11, 13 at the end of its out stroke, and so hemispherical recesses 42, 43 to co-operate in the manner hereinbefore described with the recesses 39, 40 respectively, and pro vide a spherical combustion-chamber at each end of the cylinder; A pair of fuel jets arranged as in Figure 5 are provided at each end of the cylinder, as shown at 44 and 45, to supply the liquid fuel to the respective combustion-chambers. The sca-venging air is admitted through ports 46 which impart to it a whirling motion, as indicated by the arrow 47, and the exhaust ports are indicated at 48. Both sets of ports are situated at the middle ofthe length of the cylinder so as to be uncovered by the piston at the end of its working stroke. Figure 9 shows a section at rightangles to the plane of Figure 7 and shows the piston rods 49 and also the grooves 50, 51 formed in the wall of the spherical coinbustion-chamber to permit the desired distribution of the fuel in, a fan-shaped spray.

In all the constructions and arrangements hereinbefore described, it is preferable that the concave walls of the combustionchamber should be maintained at a high temperature, say about red heat, during the normal running of the engine, in order to obtain the most satisfactory results.

What I claim as my invention and desire to secure by Letters Patent is An internaLcombustion engine characterized by the provision of a combustionchamber which is situated within the cylinder, the said chamber being formed by two concave walls with their concavities presented towards one another, there being relative movement between the concave walls in the axial direction of the cylinder, in combination with means for injecting the air for combustion into the combustionchamber so that it has a whirling motion about an axis parallel with the axis of the cylinder, and a fuel-injecting device that is set to deliver a flat fan-shaped jet of fuel oil spray into the whirling body of air as a curtain situated in the plane containing the axis about which the whirling of the air was primarily set up.

In testimony whereof I aflix my signature.

KARL OTTO KELLER. 

